Needle bar release device

ABSTRACT

A needle bar release device having a latch release member that is manually movable, or automatically movable by a solenoid, into engagement with a coupling member to unlatch the coupling member from a needle bar drive member. The latch release member is pivoted by the solenoid during automatic operation and slidably displaced on a frame during manual operation. The device also includes biasing springs for reversing the manually imposed slidable movement and automatically imposed pivotal movement of the latch release member.

United States Patent 1191 Adams et al. Man-25, 1975 NEEDLE BAR RELEASEDEVICE [75] Inventors: Kenneth D. Adams, Madison; John 53 j 'r pj fi q gEd d Pt h k, b orney, gen or lI'Hl ars a reen; war

e mm a mgac 0th of N J L. Bell; Robert E. Smith [73] Assignee: TheSinger Company, New York,

1 NY. [57] ABSTRACT [22] Fil d; S p[,13,1974 A needle bar release devicehaving a latch release 1 member that is manually movable. orautomatically [2]] Appl 505829 movable by a solenoid, into engagementwith a coupling member to unlateh the coupling member from a [52] U.S.Cl. 112/221 needle bar drive memberx The latch release member is [51]Int. Cl D05b 55/16 pivoted y the solenoid during automatic Operation[58] Field of Search 1 12/221, 220, 218 R, 158 R and slidably displacedon a frame during manual operation. The device also includes biasingsprings for re- [56] Refe enc Cit d versing the manually imposedslidable movement and UNITED STATES PATENTS automatically imposedpivotal movement of the latch 3,782,311 1/1974 Adams ct al. .1 112/158 Rrekzase member 3.815.529 6/1974 Adams et a1 112/221 X 11 Claims, 4Drawing Figures NEEDLE BARRELEASE DEVICE BACKGROUND OF THE INVENTIONThis invention relates to devices for interrupting the regular formationof stitches in a sewing machine and more particularly to a solenoidactuated needle bar release mechanism in a skip stitch device.

The usual skip stitch device in a sewing machine is normally dormantduring regular sewing and is generally activated only when a bastingoperation is required. One known way of obtaining a skip stitch functionin a sewing machine is to release a coupling between the needle bar andthe needle bar drive means at prescribed intervals corresponding to adesired extended spacing between basting stitches. The needle barcoupling can be released automatically, for example, by a cam controlledmechanism as disclosed in U.S. Pat. No. 3,782,311 issued Jan. 1, 1974,or manually, for example, by shifting a slide bar as disclosed in U.S.Pat. No. 3,815,529 issued June 11, 1974.

It has been found desirable to include both a manual and automaticneedle bar release device in one sewing machine such as disclosed inU.S. Pat. No. 3,815,529. However, the inclusion of separate manual andautomatic needle bar release devices in one sewing machine requires anintricate arrangement of parts because each device employs a separatemember for releasing the coupling between the needle bar and the needlebar drive means.

it is thus desirable to provide a needle bar release device which can bemanually or automatically operated in a convenient manner by a singlelatch release member to disengage the coupling between the needle barand the needle bar drive means.

Among the several objectsof the present invention may be noted theprovision of a novel needle bar release mechanism for a skip stitchdevice; a novel needle bar release mechanism wherein a single latchrelease member can be actuated manually or automatically as desired; anovel needle bar release device actuatable by a solenoid; and a novelneedle bar release device having a latch release member that is manuallyslidable or automatically pivotable with repsect to a sewing machinehead frame. Other objects and features will be in part apparent and inpart pointed out hereinafter.

SUMMARY or THE INVENTION The present invention relates to a novel needlebar release mechanism for a sewing machine skip stitch device. Therelease mechanism, in the preferred embodiment, includes a latch releasemember pivotally mounted to, and slidable on a frame that accommodatesreciprocatory movement of an endwise reciprocable needle bar. One end ofthe latch release member is engageable with a solenoid actuated leverthat pivots the latch release member against a spring biased latchingarrangement on a needle bar coupling member to couplingmember from theneedle bar drive member when the two members are manually orautomatically disconnected by the latch release member.-

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

DESCRIPTIONOF THE DRAWING 1n the accompanying drawing:

FIG. 1 is a perspective view of a needle bar release deviceincorporating the present invention;

FIG. 2 is an enlarged perspective view of the needle bar couplingmechanism;

FIG. 3 is an enlarged fragmentary perspective view of the latch releasemember and the solenoid actuated lever; and

FIG. 4 is a top view of the needle bar release device.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawing.

DESCRIPTION OF A PREFERRED, EMBODIMENT Referring to the drawing for adetailed description of the present invention, the head frame portion ofa straight stitch sewing machine is generally indicated by referencenumber 10. A shiftable presser bar 12 and a needle bar 14 for carrying aneedle 16 are mounted in the frame 10 in the usual manner as disclosedin detail in the U.S. Pat. No. 2,822,771 of Feb. 11, 1958. A needle bardrive member 18 for providing endwise reciprocation of the needle bar 14in the frame 10, as disclosed in detail in the U.S. Pat. No. 3,815,529,issued June 1 l, 1974, is slidably mounted on the needle bar 14 forreciprocation by any suitable drive means (not shown) such as disclosedin detail in U.S. Pat. No. 2,822,771. The needle bar drive member 18includes a pair of spaced flanges 20 and 22, and a drive pin 24engageable by the previously referenced drive means (not shown).

A coupling member 26 such as disclosed in U.S. Pat. No. 3,815,529comprises a block portion 28 fixed to the needle bar 14 by a screw 30.The coupling member 26 includes latching means for releasably connectingthe coupling member, 26 to the needle bar drive member 18. The latchingmeans comprise a first latch member 32 pivotally mounted on a post 34affixed to the block portion 28. A trigger extension 36 at one end, ofthe first latch member 32 is bent away and upwardly from the blockportion 28 and an arm 38 is formed at the opposite end of the firstlatchmember 32 extending beyond the block portion 28. The latching meansfur-.

ther comprise a second latch member 40 pivotally mounted on a shoulderscrew 42 that is locked to the block portion 28 by a lockscrew 44. Astub 46 formed on the second latch member 40 extends toward the arm 38of the first latch member 32. A latch extension 48 (FIG. 2) formed onthe second latch member 40 is bent toward the needle bar 14, and biasedinto engagement with the flange 20 of the needle bar drive member 18 bya biasing spring 50 on the shoulder screw 42. The biasing spring 50effects movement of the stub 46 into engagement with the arm 38 of thefirst latch member 32. A retraction spring 49 is connected at one end tothe block 28 by means of a post 51 on the block 28 or any other suitableconnecting point on the block 28. The opposite end of the spring 49 isconnected to an upper cross member 53 of the frame .10.

An elongated latch release member 52 having a cam slot 54 with upper andlower cam portions 56 and 58 respectively is supported at the slot 54 ona post 60 in cent'the latch release member 52. The latch release member52 includes a main body portion 66 having a narrow flange section 68terminating at a notch 70 in the main body portion 66.

An upper scoop shaped free end portion 72 of the latch release member 52is formed with a cam recess 74 having upper and lower cam portions 76and 78 with contours identical to the upper and lower cam portions 56and 58 of the cam slot 54. A guide member comprising a shoulder screw 80is disposed on the upper cross member 53 of the frame for engagementwith the cam recess 74. The upper free end portion 72 of the latchrelease member 52 also includes a bent portion 84 projecting away fromthe upper cross member 53.

A return spring 86 has an upper end connected to the main body portion66 of the latch release member 52 at a post 88 and an opposite lower endconnected to the frame leg 62 at the post 60. Under this arrangement thereturn spring 86 urges the upper cam portions 56 and 76 of the cam slot54 and the cam recess 74 into engagement with the post 60 and theshoulder screw 80.

The latch release member 52 also includes a tail portion 90 dependingfrom the main body portion 66 below a lower cross member 92 of the frame10. A lower end flange 94 of the tail portion 90 is bent under the lowercross member 92.

Control means for automatically actuating movement of the latch releasemember 52 include a solenoid 96 mounted in a solenoid frame 98 that issuspended from a cantilevered arm 100 of a support plate 102. Thesolenoid includes electrical leads 104 and 106 connected to any suitableknown switching device (not shown), and an armature 108 extendingthrough an opening (not shown) in a flange 110 of the support plate 102.The support plate 102 is anchored to a base 112 by screws 114, the base112 being formed as an adjunct to or as part of the frame 10. v

A link member 116 is pivotally supported on a post 118 affixed to thesupport plate 102. The link member 116 includes an arm 120 connected bya rod 122 to a collar 124 on a free end of the solenoid armature 108.The link member 116 also includes an arm 126 extending toward the uppercross member 53 for engagement with the upper bent portion 84 of thelatch release member 52.

When the needle bar release mechanism is not in operation the triggerextension 36 under the influence of the biasing spring 50 bears againstthe flange 68 to urge the free end portion-72 of the latch releasemember 52 v against the shoulder screw 80. For automatic operation Ibiasing spring 50 to permit the narrow flange 68 to engage the triggerextension 36 of the first latch member 32 thus causing the first latchmember 32 to pivotin a counterclockwise direction (FIG. 1) about thepost 34. The arm 38 of the first latch member 32 pivots against the stub46 of the second latch member 40 in opposition to the force of thespring 50 causing clockwise movement of the second latch member 40 (FIG.

4 1). The latch extension 48 (FIG. 2) of the second latch member 40 thuspivots away from the flange 20 of the needle bar drive member 18 todisconnect the coupling member 26 from the needle bar drive member 18.With the coupling member 26 thus free of the needle bar drive member 18the retraction spring 49 elevates the coupling member 26 and the needlebar member 14 with respect to the upper and lower cross members 53 and92 of the frame 10. The needle bar drive member 18 then reciprocates onthe needle bar 14 without influencing reciprocation of the needle bar14.

Each time the needle bar drive member 18 completes an upper stroke onthe needle bar 14 the flange 20 is positioned for relatching by thelatch extension 48 under the influence of the biasing spring 50. Howeversuch relatching cannot occur while the solenoid is energized because theinteraction between the solenoid lever arm 126, the latch release member52, the first latch member 32 and the second latch member 40 maintainsthe latch extension 48 away from the needle bar 14 to prevent engagementbetween the latch extension 48 and the flange 20.

Deenergization of the solenoid 96 permits the biasing spring 50 to urgethe second latch member 40 to pivot in av counterclockwise directionabout the shoulder screw 42 and allow the latch extension 48 of thesecond latch member 40 to move toward the needle bar 14 for couplingengagement with the flange 20 of the needle bar drive member 18. Suchreengagement permits further reciprocation of the needle bar 14 by theneedle bar drive member 18. The biasing spring 50 also influencesmovement of the stub 46 of the second latch member 40 against the arm 38of the first latch member 32 to cause the trigger extension 36 to bearagainst the flange 68 of the latch release member 52 enabling the freeend portion 72 to again contact the shoulder screw 80. A lower lip 128(FIG. 1) on the first latch member 32 below the trigger extension 36 isbent around the block portion 28 toward the post 51. The lower lip 128can thus engage the block 28 to limit clockwise pivoting of the firstlatch member 32 under the influence of the biasing spring 50.

It should be noted that as the biasing spring 50 and the return spring86 maintain the latch release member 52 in a position wherein the uppercam portions 56 and 76 normally engage the post 60 and the shoulderscrew 80 the latch release member 52 undergoes pivotal movement aboutthe post 60 during energization and deenergization of the solenoid 96.It should also be noted that the notch is formed at a predeterminedposition on the main body 66 of the latch release member 52 below thereciprocatory stroke of the trigger extension 36 to avoid entrapment ofthe trigger 36 in the notch 70.

To manually operate the needle bar release mechanism the lower endflange 94 of the latch release member 52 is pushed upwardly inopposition to the return spring 86 to enable the cam slot 54 and the camrecess 74 on the latch release member 52 to slide with respect to'theframe 10 until the lower cam portions 58 and 78 of the cam slot 54 andthe cam recess 74 engage the post 60 and the shoulder screw 80. As thelatch release member 52 is moved upwardly with respect to the post 60and the shoulder screw against the force of the spring 86 it also moveslaterally toward the needle bar 14 against the force of the spring 50 toenable the narrow flange 68 to engage the trigger extension 36.

Movement of the trigger extension 36 by the latch release member 52uncouples the needle bar drive member 18 from the coupling member 26 ina manner previously described.

When pressure is removed from the lower end of the flange 94 of thelatch release member 52, the return spring 86 urges the member 52downwardly to its initial position wherein the upper cam portions 56 and76 of the cam slot 54 and the cam recess 74 engage the post 60 and theshoulder screw 80, enabling the coupling member 26 and the needle bardrive member 18 to reconnect for further reciprocation of the needle bar14 by the drive member 18 in a manner previously de' scribed.

It will be apparent to those skilled in the art that the needle barrelease mechanism disclosed herein can be adapted to zig-zag sewingmachines such as the type disclosed in U.S. Pat. No. 3,815,529. It willbe further apparent that the biasing spring 50 furnishes one forcecomponent on the latch release member 52 which pivots the member 52 backagainst the pin 80 after the solenoid 96 has been deenergized. Thereturn spring 86 furnishes a second force component on the latch releasemember 52 which lowers the member 52 after manual pressure on the lowerend flange 94 has been removed. Thus the separate force components ofthe springs 50 and 86 on the latch release member 52 operatesubstantially at right angles to each other. There fore the solenoid 96which moves the latch release member 52 at substantially-right angles tothe force of the spring 86 essentially opposes the force of the biasingspring 50 and need not overcome the total force of the spring 86 inurging the latch release member 52 pivot against the trigger extension36.

Some advantages of the novel device disclosed herein include a novelneedle bar release mechanism that can be used for automatic or manualrelease of a needle bar coupling. The mechanism can be automaticallyactuated by a relatively low powered solenoid to overcome the resistanceof the biasing spring 50 and less than the total resistance of thereturn spring 86.

In view of the above it will be seen that the several objects of theinvention are achieved and other advantageous results obtained.

As various changes can be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing, shall be interpreted as illustrative and not in a limitingsense.

Having thus set forth the nature of the invention, what is claimedherein is:

1. A needle bar release device for a sewing machine comprising, anendwise reciprocable needle bar, frame means for accommodatingreciprocatory movement of said needle bar, a reciprocating drive memberslidably mounted on said needle bar, a coupling member fixed to saidneedle bar for continuous movement with said needle bar, said couplingmember including latching means for releasably connecting said couplingmember to said drive member to transmit reciprocatory movement'of saiddrive member to said needle bar, said latching means including a latchextension movable in a first direction toward said drive member topermit said coupling member to connect to said drive member, said latchextension being movable in a second direction away from said drivemember to permit said coupling member to disconnect from said drivemember, said latching means further including first biasing means forurging said latch extension to move in said first direction, latchrelease means mounted on said frame means for pivotal movement againstsaid latching means to move said latch extension in said seconddirection, said first biasing means continuously urging said latchrelease means to pivot away from said latching means, and a solenoidmember mounted on said frame means, said solenoid member havingactuating means for causing pivotal movement of said latch release meansagainst said latching means to cause move ment of said latch extensionin said second direction to disconnect said coupling member from saiddrive member whereby said drive member slides on said needle bar withoutinfluencing reciprocatory movement of said needle bar.

2. A needle bar release device as claimed in claim 1 wherein said latchrelease means includes a pivot member on said frame and an elongatedlatch release member mounted to said pivot member for pivotable movementtoward and away from said latch release means.

3.. A needle bar release device as claimed in claim 2 further comprisingsecond biasing means connected to said elongated latch release memberand wherein said elongated latch release member is formed with a slotengageable with said pivot member to permit slidable movement of saidlatch release member with respect to said pivot member, said springbeing connected to said latch release member to continuously urge saidlatch release member to position one end of said slot against said pivotmember.

4. A needle bar release device as claimed in claim 3 wherein saidelongated latch release member further includes cam means comprising afirst cam surface formed in said slot for cooperation with said pivotmember to guide said latch release member against said coupling memberwhen said latch release member is slidably moved with respect to saidpivot member in opposition to the force of said second biasing means. i

5. A needle bar release device as claimed in claim 4 further including aguide member on said frame spaced from said pivot member, said elongatedlatch release member being engageable with said guide member under theinfluence of said first biasing means.

6. A needle bar release device as claimed in claim 5 wherein saidelongated latch release member is slidable with respect to said guidemember, said cam means further including a second cam surface on saidelongated latch release member engageable with said guide member.

7. A needle bar release device as claimed in claim 6 wherein saidelongated latch release member includes a tail portion extending fromsaid frame in the direction of said needle for manual access to permitexertion of manual pressure on said tail portion to slide said latchrelease member on said frame against the force of said second biasingmeans to move the first and second cam surfaces with respect to thepivot member and the guide member, the interaction between the first andsecond cam surfaces and the pivot and guide members guiding said latchrelease member against said coupling member.

8. A needle bar release device as claimed in claim 1 wherein saidsolenoid actuating means include a plunger member and a lever movable bysaid plunger member against said latch release means when said so- I ofsaid latch extension away from said drive member to disconnect saidcoupling member from said drive member, de-energization of said solenoidpermitting said latch release means to move away from said latchingmeans under the influence of said first biasing means.

9. A needle bar release device as claimed in claim 1 further including aresilient member having one end connected to said frame means and anopposite end connected to said coupling member for retracting saidneedle bar and coupling member in said frame means when said couplingmember is disconnected from said drive means. a

10. A needle bar release device as claimed in claim 9 wherein saidcoupling member includes a block portion, said latch arm being pivotallymounted to said block portion, and said opposite end of said resilientmember being connected to said block portion.

11. A needle bar release device for a sewing machine comprising, anendwise reciprocable needle bar, frame means for accommodatingreciprocatory movementof said needle bar, needle bar drive means forreciprocating said needle bar in said frame,-coupling means for forminga detachable connection between said needle bar and said needle bardrive means, a coupling release member pivotally mounted on said framefor engagement with said coupling means to effect an uncoupling of saidcoupling means from said needle bar drive means such that said drivemeans does not influence reciprocatory movement of said needle bar, saidcoupling release member being normally disposed in a first positionwherein said coupling means remains coupled to said needle bar drivemeans and being pivotally movable from said first position to a secondposition for effecting uncoupling of said coupling means from saidneedle bar drive means, and electrical actuating means for pivotallymoving said coupling release member from its first position to itssecond position.

1. A needle bar release device for a sewing machine comprising, anendwise reciprocable needle bar, frame means for accommodatingreciprocatory movement of said needle bar, a reciprocating drive memberslidably mounted on said needle bar, a coupling member fixed to saidneedle bar for continuous movement with said needle bar, said couplingmember including latching means for releasably connecting said couplingmember to said drive member to transmit reciprocatory movement of saiddrive member to said needle bar, said latching means including a latchextension movable in a first direction toward said drive member topermit said coupling member to connect to said drive member, said latchextension being movable in a second direction away from said drivemember to permit said coupling member to disconnect from said drivemember, said latching means further including first biasing means forurging said latch extension to move in said first direction, latchrelease means mounted on said frame means for pivotal movement againstsaid latching means to move said latch extension in said seconddirection, said first biasing means continuously urging said latchrelease means to pivot away from said latching means, and a solenoidmember mounted on said frame means, said solenoid member havingactuating means for causing pivotal movement of said latch release meansagainst said latching means to cause movement of said latch extension insaid second direction to disconnect said coupling member from said drivemember whereby said drive member slides on said needle bar withoutinfluencing reciprocatory movement of said needle bar.
 2. A needle barrelease device as claimed in claim 1 wherein said latch release meansincludes a pivot member on said frame and an elongated latch releasemember mounted to said pivot member for pivotable movement toward andaway from said latch release means.
 3. A needle bar release device asclaimed in claim 2 further comprising second biasing means connected tosaid elongated latch release member and wherein said elongated latchrelease member is formed with a slot engageable with said pivot memberto permit slidable movement of said latch release member with respect tosaid pivot member, said spring being connected to said latch releasemember to continuously urge said latch release member to position oneend of said slot against said pivot member.
 4. A needle bar releasedevice as claimed in claim 3 wherein said elongated latch release memberfurther includes cam means comprising a first cam surface formed in saidslot for cooperation with said pivot member to guide said latch releasemember against said coupling member when said latch release member isslidably moved with respect to said pivot member in opposition to theforce of said second biasing means.
 5. A needle bar release device asclaimed in claim 4 further including a guide membeR on said frame spacedfrom said pivot member, said elongated latch release member beingengageable with said guide member under the influence of said firstbiasing means.
 6. A needle bar release device as claimed in claim 5wherein said elongated latch release member is slidable with respect tosaid guide member, said cam means further including a second cam surfaceon said elongated latch release member engageable with said guidemember.
 7. A needle bar release device as claimed in claim 6 whereinsaid elongated latch release member includes a tail portion extendingfrom said frame in the direction of said needle for manual access topermit exertion of manual pressure on said tail portion to slide saidlatch release member on said frame against the force of said secondbiasing means to move the first and second cam surfaces with respect tothe pivot member and the guide member, the interaction between the firstand second cam surfaces and the pivot and guide members guiding saidlatch release member against said coupling member.
 8. A needle barrelease device as claimed in claim 1 wherein said solenoid actuatingmeans include a plunger member and a lever movable by said plungermember against said latch release means when said solenoid is energizedsuch that said latch release means moves against said latching means tocause movement of said latch extension away from said drive member todisconnect said coupling member from said drive member, de-energizationof said solenoid permitting said latch release means to move away fromsaid latching means under the influence of said first biasing means. 9.A needle bar release device as claimed in claim 1 further including aresilient member having one end connected to said frame means and anopposite end connected to said coupling member for retracting saidneedle bar and coupling member in said frame means when said couplingmember is disconnected from said drive means.
 10. A needle bar releasedevice as claimed in claim 9 wherein said coupling member includes ablock portion, said latch arm being pivotally mounted to said blockportion, and said opposite end of said resilient member being connectedto said block portion.
 11. A needle bar release device for a sewingmachine comprising, an endwise reciprocable needle bar, frame means foraccommodating reciprocatory movement of said needle bar, needle bardrive means for reciprocating said needle bar in said frame, couplingmeans for forming a detachable connection between said needle bar andsaid needle bar drive means, a coupling release member pivotally mountedon said frame for engagement with said coupling means to effect anuncoupling of said coupling means from said needle bar drive means suchthat said drive means does not influence reciprocatory movement of saidneedle bar, said coupling release member being normally disposed in afirst position wherein said coupling means remains coupled to saidneedle bar drive means and being pivotally movable from said firstposition to a second position for effecting uncoupling of said couplingmeans from said needle bar drive means, and electrical actuating meansfor pivotally moving said coupling release member from its firstposition to its second position.